Potential Risks of PM2.5-Bound Polycyclic Aromatic Hydrocarbons and Heavy Metals from Inland and Marine Directions for a Marine Background Site in North China

Ambient PM2.5-bound ions, OC, EC, heavy metals (HMs), 18 polycyclic aromatic hydrocarbons (PAHs), 7 hopanes, and 29 n-alkanes were detected at Tuoji Island (TI), the only marine background atmospheric monitoring station in North China. The annual PM2.5 average concentration was 47 ± 31 μg m−3, and the average concentrations of the compositions in PM2.5 were higher in cold seasons than in warm seasons. The cancer and non-cancer risks of HMs and PAHs in cold seasons were also higher than in warm seasons. BaP, Ni, and As dominated the ∑HQ (hazard quotient) in cold seasons, while the non-carcinogenic risk in warm seasons was mainly dominated by Ni, Mn, and As. The ILCR (incremental lifetime cancer risk) values associated with Cr and As were higher in the cold season, while ILCR-Ni values were higher in the warm season. The backward trajectory was calculated to identify the potential directions of air mass at TI. Through the diagnostic ratios of organic and inorganic tracers, the sources of particulate matter in different directions were judged. It was found that ship emissions and sea salt were the main sources from marine directions, while coal combustion, vehicles emissions, industrial process, and secondary aerosols were the main source categories for inland directions. In addition, potential HM and PAH risks from inland and marine directions were explored. The non-cancerous effects of TI were mainly affected by inland transport, especially from the southeast, northwest, and west-northwest. The cancerous effects of TI were mainly simultaneously affected by the inland direction and marine direction of transport.

Distribution of Polychlorinated Naphthalenes in Sediment From Industrialized Coastal Waters of Korea With the Optimized Cleanup and GC-MS/MS Methods

Limited studies have been conducted on polychlorinated naphthalenes (PCNs) in the coastal environment worldwide. In this study, analytical methods were optimized for 18 PCN congeners in sediment using a multi-layer silica gel column and a gas chromatograph coupled to tandem mass spectrometry (GC-MS/MS). The optimized analytical methods of PCNs were employed for sediment samples from heavily industrialized bays of Korea to assess the occurrence, contamination, potential sources, and ecotoxicological concerns. PCNs were detected in all sediment samples, indicating ubiquitous contamination in industrialized coastal regions of Korea. Total concentrations and toxic equivalents (TEQs) of PCNs ranged from 0.99 to 21,500 (mean: 568) pg/g dry weight and from 1.72 × 10–5 to 18.8 (mean: 0.52) pg TEQ/g dry weight, respectively, which were within the ranges reported by other studies. A clear decreasing gradient was observed for the sedimentary PCNs from inner to outer parts of the bays, streams, and rivers. This result indicates that industrial activities are primary sources of PCNs. The highest PCN concentrations were observed in sediment close to non-ferrous and petrochemical industries, indicating potential sources. CNs 73 and 52 were predominant congeners of PCNs in all sediment samples. Diagnostic ratios and non-parametric multidimensional scaling analysis showed that the potential primary sources of PCNs are thermal-related emissions and the use of PCB technical mixtures. Although a few sediment samples exceeded the sediment quality guidelines of TEQs, the cumulative risks by dioxin-like contaminants may be caused for almost all coastal zones surveyed. This is the first report on PCNs in sediment from Korean coastal waters.

Toxicity and Risks Assessment of Polycyclic Aromatic Hydrocarbons in River Bed Sediments of an Artisanal Crude Oil Refining Area in the Niger Delta, Nigeria

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants that possess serious risks to human health and the environment. Forty riverbed sediments samples were collected in mangrove river bed sediments where artisanal refining of crude oil takes place in the Niger Delta of Nigeria. The concentration, occurrence, distribution, toxicity and health risk of sixteen priority PAHs (16PAHs) were analysed in the samples. Apart from Nap, Acy, BkF, InP and DbE, all the other PAHs were present in all the sampled points of the studied area with BbF and BaA recording the highest mean values. The range and mean of the total PAHs (∑16PAHs) of this study are 23.461–89.886 mg/kg and 42.607 ± 14.30 mg/kg dry weight (dw), which is classified as heavily contaminated when compared to the European classification of PAHs pollution in soil (>1.0 mg/kg). The range of the effect range factors used to assess the risk of PAHs in an ecosystem (Effect rang-low (ER-L) and Effect range-median ER-M) of this study is from 0.953 to 8.80 mg/kg. PAHs below ER-L (4.0 mg/kg) indicate no toxic effect, but values above ER-M (44.79 mg/kg) indicate toxic effects to the sediments, its resources and, ultimately, the public that consumes the resources thereof; hence, the study area falls within the contaminated category. The occurrence of the high molecular weight (HMW) PAHs (73.4%) supersedes those of the lower molecular weight (LMW) PAHs (26.6%). The diagnostic ratios and principal component analysis suggest that the main contributors of PAHS into the sediments are the combustion of biomass, fossil fuel (crude oil) and pyrogenic sources. The toxic equivalent quotient (TEQ) and mutagenic equivalent quotient (MEQ) of PAHs ranged from 2.96 to 23.26 mgTEQ/kg dw and 4.47 to 23.52 mgMEQ/kg dw, and the total mean toxic equivalency quotient (∑TEQ) (15.12 ± 8.4 mg/kg) is also greater than the safe level of 0.6 mg/kg, which indicates high toxicity potency. The mean incremental lifetime cancer risks (ILCRs) of human exposure to PAHs shows that both adults TotalILCR adults (6.15 × 10−5) and children TotalILCR children (2.48 × 10−4) can be affected by dermal contact rather than ingestion and inhalation. Based on these findings, the appropriate regulatory bodies and other organs of government in the region should enforce outright stoppage of the activities of these illegal artisans who do not have control mechanisms for loss control at the site and carry out appropriate clean-up of the area.

Investigating the concentration levels, distribution patterns, source identification and health risk assessment of PAHs, n-alkanes, hopanes, and steranes in deposited dust of Mashhad, Iran

Deposited dust (DD) in urban environments contains carcinogenic organic compounds. The Indoor air quality is greatly affected by heating, ventilation, and air conditioning systems (HVAC), and in the Middle East most of the buildings are equipped by HVAC on top of them. It is possible that the DD on the roof near this equipment would be transferred to an indoor area. For these reasons, 40 samples of the over the roof DD were prepared, and organic compounds (16PAH compounds, 20n-alkane homologs, 8hopanes, and 6steranes) of DD were extracted using Soxhlet and analyzed by GC-MS. Source identification of organic compounds conducted by ring classification, diagnostic ratios, and factor analysis (FA). The results showed that the average (±SD) of total PAHs, n-alkanes, hopanes and steranes in DD were 1356.00 (±291.45) ng kg−1dw, 3211.65 (±969.18), 146.37 (±79.45) and 469.76 (±188.25) µg.g_1dw, respectively. The highest concentration of organic compounds was in the city center, where traffic congestion is common. Diagnostic ratios of n-alkanes results showed the dominant source is vehicular emission. FA results indicated vehicular emission and biogenic sources. In agreement, the results of sterane and hopane profiles confirm these results. On the other hand, the PAHs diagnostic ratios results indicated petroleum combustion sources. In this regard, FA findings showed combustion from vehicular emission and natural gas and wood combustion were the main factors. Furthermore, the incremental lifetime cancer risk was calculated as 8.45× 10−12 for children and 9.80 × 10−7 for adults, and the imposed risk was negligible.

One-Century Sedimentary Record, Sources, And Ecological Risk of Polycyclic Aromatic Hydrocarbons in Dianchi Lake, China

In this study, the sedimentary records, sources, and ecological risks of polycyclic aromatic hydrocarbons (PAHs) in Dianchi Lake were analyzed. The concentration ranges of ΣPAH16 in the sediments of Dianchi Lake were 368–990 ng/g, with an average value of 572 ng/g, peaking in 1988. Economic development and rapid population growth, as well as the rapid growth of coal consumption, have a greater impact on the HMW PAHs than on the LMW PAHs in the sedimentary environment. The results of the diagnostic ratios and PCA model show that the main sources of PAHs were coal and biomass combustion, as well as fossil fuel combustion sources in individual years. The risk assessment results showed that the PAH concentrations in the sediment were within a safe range. In the past 100 years of sediment pore water, except for Phe, which reached chronic toxic pollution levels in some years, other 2-3 ring LMW PAHs have been within a safe range. With the development of industrialization and urbanization, the burning of fossil fuels such as coal and petroleum has increased, and some of the 4-6 ring HMW PAHs have reached chronic toxicity or even acute toxicity in the sediment pore water.

Monitoring of Polycyclic Aromatic Hydrocarbon Levels in Mussels (Mytilus galloprovincialis) from Aquaculture Farms in Central Macedonia Region, Greece, Using Gas Chromatography–Tandem Mass Spectrometry Method

A new sensitive and selective gas chromatography tandem mass spectrometry (GC-MS/MS) method was developed for the analysis of 26 polycyclic aromatic hydrocarbons (PAHs), including 16 Environmental Protection Agency (EPA) and 15 + 1 European Union (EU) PAHs, in mussel samples from aquaculture farms in Thermaikos and Strymonian Gulf, Central Macedonia Region, in three sampling periods. Concentrations were found at moderate to low values at all sampling sites, without exceeding maximum levels set by EU. Low molecular weight PAHs were predominant in all samples. Seasonal variation of the concentrations was observed; values were slightly higher in the winter period. Use of diagnostic ratios for potential sources of PAHs showed both petrogenic and pyrolitic origin. In comparison to other related studies of mussels from the Mediterranean Sea, Greek mussels cultivated in the studied gulfs are low in contaminants due to minimal environmental pollution effects. Low concentrations of PAHs are in compliance with the low values of other POPs which were found in the mussels.

Distribution Trends and Source Diagnosis of Polycyclic Aromatic Hydrocarbons (PAHs) in Sediments of Imiringi River

The environmental menace caused by hydrocarbon releasing activities on water bodies have remained a cause for great concern. Such activities are accompanied by the release of highly toxic and carcinogenic polycyclic aromatic hydrocarbons (PAH), which are easily biomagnified across the food chain, ultimately aggravating adverse health conditions in human. This study was aimed at identifying the most important environmental contributors of PAHs in sediments of the Imiringi river. Owing to the activities of oil facilities among other anthropogenic influences, water bodies are inundated with hydrocarbon pollutants which settle within river bed sediments, thereby, playing an important role in the redistribution of contaminants. The applied diagnostic ratios (Phenanthrene/Anthracene, Fluorene/Fluorene + Pyrene, Fluoranthene/Fluoranthene + Pyrene, pyrogenic index and total index) revealed the presence of mixed source of PAHs (pyrogenic and petrogenic). PAH concentrations ranged from <0.01 to 3,965.4 µg/kg with most detected compounds exceeding regulatory limits. The high molecular mass PAHs (4 - 6 ring HPAHs) represents the primary source showing 94.29% distribution, while the low molecular mass PAHs (2 - 3 ring LPAHs) recorded trace concentrations of about 5.71% of total PAHs. Principal component analysis (PCA) revealed Indeno(1,2,3-cd)pyrene and Dibenz(a,h)anthracene as principal PAH components in the environment. In addition, Pearson correlation showed Benzo(k)fluoranthene and Benzo(b)fluoranthene as the most positively correlating PAH species in sediment. Overall, the midstream section of the river was relatively more polluted than the up and down-river locations. Most notably, HPAHs recorded higher concentrations than the LPAHs. This may be due to intensive agricultural practices such as bush incineration, while waste dumps along the river bank remain tangible pyrogenic PAH contributors. On the other hand, trace amounts of observed petrogenic PAHs in some locations are possibly spill-over’s from oil bunkering activities and infiltrations from nearby oil installations.